Page 241 - Carbon Nanotube Fibres and Yarns

Sensors based on CNT yarns 231

0.8

0.7
(a)
(a) HPR93A
0.6
(b) HPR93B
r (mΩ cm) 0.5 (c) HPR93C (c)

0.4
0.3
(b)
0.2
1 10 100
(A) T (K)

10 9 Composite, 53% stretch
Annealed, 76% stretch
10 7

10 5
r (Ω cm) 10 3

10 1

10 −1

10 −3
1 10 100
(B) Temperature (K)
Fig. 9.9 (A) Four-point probe resistivity-temperature for three neat CNT fibers. The resis-
tivity decreases at all temperatures as alignment improves. Nonmetallic behavior at low
T levels off as T → 0 ~nondivergent behavior! while metallic behavior is observed above
200 K [9]. (B) Resistivity-temperature curve for composite (53% stretch) and annealed
(76% stretch) CNT fibers (log-log scale) [75]. (Source of (A): W. Zhou, J. Vavro, C. Guthy,
K.I. Winey, J.E. Fischer, L.M. Ericson, et al., Single wall carbon nanotube fibers extruded from
super- acid suspensions: preferred orientation, electrical, and thermal transport, J. Appl.
Phys. 95 (2004) 650. Source of (B): S. Badaire, V. Pichot, C. Zakri, P. Poulin, P. Launois, J. Vavro,
et al., Correlation of properties with preferred orientation in coagulated and stretch-aligned
single-wall carbon nanotubes, J. Appl. Phys. 96 (2004) 7509.)